Pearly penile papules

These are small, flesh-coloured lumps normally found on the head of the penis. They usually go all the way around the penis head in one or two rows. These lumps are normal. They're not sexually transmitted or caused by bad hygiene. They don't cause symptoms and don't require treatment.

Fordyce spots

Fordyce spots are small yellowish or white spots on the head or shaft of the penis. Fordyce spots are sebaceous glands (tiny glands found near the surface of your skin) without hair follicles. They can also appear on the inside of the cheeks or on the lips, and are present in 80-95% of adults. Fordyce spots are generally harmless and don't need treatment.

Lymphocele

This is a hard swelling that suddenly appears on the shaft of the penis after sex or masturbation. It happens when the lymph channels in your penis are temporarily blocked. Lymph is a clear fluid that forms part of the body's immune system. The swelling should soon subside and won't cause any permanent problems.

Lichen planus

Lichen planus is a non-infectious, itchy rash of purple-red bumps that can affect many areas of the body, including the penis.

Sores or ulcers

A painful blister or sore on your penis could be caused by herpes, which is an STI caused by the herpes simplex virus. A painless sore or ulcer on your penis could be caused by syphilis (another STI).

Peyronie's disease

Peyronie's disease is an uncommon condition that causes a thickened area or hard lump (plaque) in the shaft of the penis. This can cause the penis to become curved when it's erect. For more information, read Is it normal to have a curved penis?

Molluscum contagiosum

Molluscum contagiosum is a viral skin infection. It causes small, firm, raised spots on the skin, which usually form in little clusters. They can affect the penis and general groin area, in which case it is considered an STI.

Cancer of the penis

Penile cancer is a rare type of cancer that can cause a sore or lump on the penis, most commonly on the head of the penis. Read more about penile cancer.